Make article indexing more efficient.

Frameworks/ArticlesDatabase/ArticlesTable.swift

@@ -277,19 +277,11 @@ final class ArticlesTable: DatabaseTable {
 			self.callUpdateArticlesCompletionBlock(newArticles, updatedArticles, completion) //7
 
 			// 8. Update search index.
-			var articlesToIndex = Set<Article>()
 			if let newArticles = newArticles {
-				articlesToIndex.formUnion(newArticles)
+				self.searchTable.indexNewArticles(newArticles, database)
 			}
 			if let updatedArticles = updatedArticles {
-				articlesToIndex.formUnion(updatedArticles)
+				self.searchTable.indexUpdatedArticles(updatedArticles, database)
-			}
-			let articleIDsToIndex = articlesToIndex.articleIDs()
-			if articleIDsToIndex.isEmpty {
-				return
-			}
-			DispatchQueue.main.async {
-				self.searchTable.ensureIndexedArticles(for: articleIDsToIndex)
 			}
 		}
 	}

Frameworks/ArticlesDatabase/SearchTable.swift

@@ -45,6 +45,10 @@ final class ArticleSearchInfo: Hashable {
 		self.searchRowID = searchRowID
 	}
 
+	convenience init(article: Article) {
+		self.init(articleID: article.articleID, title: article.title, contentHTML: article.contentHTML, contentText: article.contentText, summary: article.summary, searchRowID: nil)
+	}
+
 	// MARK: Hashable
 
 	public func hash(into hasher: inout Hasher) {
@@ -93,6 +97,17 @@ final class SearchTable: DatabaseTable {
 		let indexedArticles = articleSearchInfos.filter { $0.searchRowID != nil }
 		updateIndexForArticles(indexedArticles, database)
 	}
+
+	/// Index new articles.
+	func indexNewArticles(_ articles: Set<Article>, _ database: FMDatabase) {
+		let articleSearchInfos = Set(articles.map{ ArticleSearchInfo(article: $0) })
+		performInitialIndexForArticles(articleSearchInfos, database)
+	}
+
+	/// Index updated articles.
+	func indexUpdatedArticles(_ articles: Set<Article>, _ database: FMDatabase) {
+		ensureIndexedArticles(articles.articleIDs(), database)
+	}
 }
 
 // MARK: - Private